The term 'Tributary of the Mississippi' can be summarized by the five-letter word 'Yazoo'. The Yazoo River is a tributary of the Mississippi River located in the U.S. states of Mississippi and Louisiana. It is approximately 200 miles long and is an important source of water for the region. The Yazoo River is also known for its rich history, having been used by Native Americans for centuries before being explored by Europeans in the 1700s.